Those shoes are a disadvantage in the mountains and most technical terrain.
It's not Walmsley's fault (although he's not recovered from Western States), but too much foam between the foot and the terrain. No HOKA athlete has ever won a major mountain race like UTMB - it's always Salomon or Asics guys.
Not a great trail shoe. Great for flat dirt running, but get into scree and the skags like Norway and Scotland, you have no chance with that footwear choice.